Estimación no-invasiva de la presión de pulso arterial a partir de imágenes ecográficas en modo B

Abstract

Pulse pressure is not constant throughout the arterial tree increasing centrifugally. Therefore, use of pulse pressure at one arterial site, such as brachial artery, as surrogate for pulse pressure at another arterial site may be erroneous. Applanation tonometry allows the non invasive determination of arterial pulse pressure in both central and peripheral arteries. However it cannot be applied to all subjects (such as obese) and at all arterial sites. In contrast, B-mode echographic derived arterial diameter waveforms can be obtained at more arterial sites and also in a majority of obese subjects. The aim of this study was to investigate the accuracy of the pulse pressure assessed by calibration of echographic arterial diameter waveforms. The left common carotid artery of 49 normotensive subjects (NT) and 45 hypertensive (HT) patients were measured non invasively by using tonometry and automatic analysis of B-mode echographic images, to obtain instantaneous pressure (P) and diameter (D) signals. Calibration of carotid D and P was assessed from tonometer brachial artery waves and sphygmomanometer, assuming mean minus diastolic pressure constant throughout the arterial tree. Pulse pressure from calibrated diameter waves was 4±2 mmHg (NT vs. HT not significant) lower than pulse pressure from tonometer calibrated pressure waves (used as reference method), with a correlation coefficient of r=-0.99 (p<0.05). In conclusion, pulse pressure obtained from alternatively calibrated B-mode derived arterial diameter waveforms demonstrates good accuracy within the acceptability limits of the AAMI criteria. © Springer-Verlag Berlin Heidelberg 2007.